Average flower is 17.1% in one state with legal sales of recreational marijuana, Colorado, much higher than the national average (HIDTA, 2017), and as high as 30% THC in some samples (NBC News report). It should be noted that variation in testing results is quite high between laboratories (Jikomes and Zoroob, 2018).

Cougle JR et al. (2015). Quality of life and risk of psychiatric disorders among regular users of alcohol, nicotine, and cannabis: An analysis of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC). J Psychiatr Res., 66-67, 135-141

Di Forti M, et al. Proportion of patients in South London with first-episode psychosis attributable to use of high potency cannabis: a case-control study. Lancet Psychiatry. 2015;2(3):233-8.

Raemakers, JG Driving Under the Influence of Cannabis: An Increasing Public Health Concern. JAMA published online March 26, 2018 Regular cannabis users wrongfully believe that cannabis does not affect their driving performance or that they can compensate for cannabis-associated impairment. Raemakers_2018 JAMA driving editorial.pdf

Olfson M, Wall M Cannabis Use and Risk of Prescription Opioid Use Disorder in the United States American J Psychiatry. Cannabis use, even among adults with moderate to severe pain, was associated with a substantially increased risk of nonmedical prescription opioid use at 3-year follow-up. https://doi-org.proxy.hsi.ucdenver.edu/10.1176/appi.ajp.2017.17040413

Graph provided by The Marijuana Report/National Families in Action. March 2018

Olfson M, Wall M Cannabis Use and Risk of Prescription Opioid Use Disorder in the United States, American J Psychiatry. Cannabis use, even among adults with moderate to severe pain, was associated with a substantially increased risk of nonmedical prescription opioid use at 3-year follow-up. https://doi-org.proxy.hsi.ucdenver.edu/10.1176/appi.ajp.2017.17040413